An efficient quick-setting hole-sealing material and its preparation method

Abstract

The present invention discloses an efficient quick-setting hole-sealing material and its preparation method, which relates to the technical field of polymer modified materials. The hole-sealing material is composed of a cement matrix, a polymer modifier, aluminum sulfate, quartz sand, a polycarboxylate superplasticizer, magnesium hydroxide, and a cellulose ether thickener. By optimizing the proportions of these components, the material exhibits excellent tightness and construction efficiency in mine gas drainage. Its rapid setting property enables it to form an effective seal in a short time and is suitable for emergency construction scenarios. In addition, the introduction of the polymer modifier significantly improves the mechanical strength and durability of the material, while reducing the permeability coefficient and enhancing safety. The preparation method is simple, only requiring mixing the components and adding an appropriate amount of water and stirring evenly. This new type of hole-sealing material not only solves the problem of easy cracking of traditional materials in high-temperature environments but also has advantages in terms of economy and is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer modified materials, and in particular to an efficient quick-setting hole-sealing material and a preparation method thereof. Background Art

[0002] Mine gas is one of the main disasters in coal mine production. Its outburst and leakage not only threaten the lives of miners but also seriously affect the normal progress of coal mine production. Gas outburst is the result of the interaction among coal seam gas pressure, coal body stress, and coal body strength, and it has the characteristics of suddenness, destructiveness, and unpredictability. To effectively prevent and control gas outburst, pre-extracting gas is the most commonly used and effective treatment method at present. However, during the gas extraction process, the hole-sealing quality directly affects the extraction effect, and the key to the hole-sealing technology lies in the performance of the hole-sealing material. Therefore, developing efficient and reliable hole-sealing materials is of great significance for improving gas extraction efficiency and reducing potential safety hazards.

[0003] At present, conventional hole-sealing methods mainly include mechanical hole-sealing method, casing hole-sealing method, clay hole-sealing method, cement mortar hole-sealing method, and polyurethane hole-sealing method, etc. Although these methods can meet the requirements of mine gas extraction to a certain extent, there are still many problems: The mechanical hole-sealing method relies on mechanical devices to seal the borehole, but its sealing effect is greatly affected by the integrity of the borehole wall surface and the installation accuracy of the mechanical device. Under complex geological conditions, it is difficult for mechanical hole-sealing to completely seal the fissures, and air leakage is likely to occur. The casing hole-sealing method achieves the sealing effect by inserting a casing into the borehole and filling it with a sealing material. However, this method is complex in construction, high in cost, and prone to failure under deep high-pressure environments. Clay was widely used in mine hole-sealing due to its good plasticity and low permeability. However, clay materials are prone to cracking and shrinking under high-temperature and dry environments, resulting in sealing failure. In addition, its construction efficiency is low and it is not suitable for large-scale applications. As a traditional hole-sealing material, cement mortar has the advantages of low cost and convenient construction. However, ordinary cement mortar has an inherent shrinkage problem and is prone to generating fissures during the setting process, thus leading to air leakage. In addition, its setting time is relatively long and it is not suitable for scenarios that require rapid construction. Polyurethane foaming materials are widely used in mine grouting due to their good expansibility and airtightness. However, these materials cannot completely fill the original fissures around the borehole during the expansion process, and the expansion force is not sufficient to squeeze and fill the fissures. In addition, the strength of polymer foaming materials is relatively low, the compressibility is relatively large, and they lack support for the borehole. At the same time, they are expensive, and large-scale use will significantly increase the production cost.

[0004] In view of the problems existing in the above-mentioned traditional methods and materials, there is an urgent need for a new type of sealing material with excellent performance to meet the requirements of mine gas extraction for efficiency, safety and economy. The ideal high-efficiency quick-setting sealing material should have the following characteristics: Rapid setting: It can complete setting in a short time to improve construction efficiency, especially in emergency situations, it can quickly form a sealing effect. High strength and stability: It has sufficient compressive strength and long-term stability to support the borehole and maintain its structural integrity. Good sealing performance: It can completely fill the borehole and the cracks around it to prevent air leakage. High temperature resistance and non-flammability: It maintains stable performance in high temperature environment and has non-flammable properties to ensure mine safety. Economical: The material cost is moderate, which is convenient for large-scale promotion and application.

[0005] In recent years, in order to overcome the shortcomings of traditional materials, some studies have begun to explore polymer-modified cement-based grouting materials. This type of material improves the performance of the cement matrix by introducing polymer modifiers, so that it has both the strength advantages of cement and the flexibility of polymers. For example: by adding polyacrylate emulsion to the cement matrix, the microstructure of the stone body can be significantly improved, and the compressive strength and toughness can be improved. This material can not only coagulate quickly, but also has good impermeability, and is a potential choice for repairing broken rock masses. By introducing inorganic ceramic components, this material can form a ceramic structure under high temperature conditions, thereby improving fire resistance and long-term stability. By combining inorganic gelling materials with organic polymers, the strength, toughness and sealing properties of the grouting material can be improved at the same time. For example, compounding polyurethane with a cement matrix can not only increase the expansion force, but also enhance the ability to fill cracks.

[0006] Although the new modified grouting materials have improved the performance of traditional materials to a certain extent, there are still some problems that need to be solved: some modified grouting materials require special processes or equipment to prepare, which increases production costs. Some modifiers perform poorly in extreme environments (such as high humidity, high temperature or low temperature), which limits their application scope. Some new materials are expensive and face economic pressure in large-scale promotion. Summary of the invention

[0007] The present invention aims to provide a high-efficiency quick-setting sealing material and a preparation method thereof, which is mainly used in the sealing technology in mine gas extraction. The invention aims to solve the problems of traditional sealing materials in terms of airtightness, construction efficiency and economy, and provide an alternative solution with excellent performance.

[0008] To achieve the above object, the present invention provides the following technical solution: An efficient quick-setting hole-sealing material, by weight, comprising the following components: Cement matrix: 40-60 parts, Polymer modifier: 5-15 parts, Aluminum sulfate: 3-8 parts, Quartz sand: 10-20 parts, Polycarboxylate superplasticizer: 0.5-2 parts, Magnesium hydroxide: 1-3 parts, Cellulose ether thickener: 0.1-0.5 parts.

[0009] Preferably, by weight, it comprises the following components: Cement matrix: 45-55 parts, Polymer modifier: 8-12 parts,

[0010] Aluminum sulfate: 3-8 parts, Quartz sand: 12-20 parts, Polycarboxylate superplasticizer: 0.5-2 parts, Magnesium hydroxide: 1-3 parts, Cellulose ether thickener: 0.1-0.5 parts.

[0011] Preferably, by weight, it comprises the following components: Cement matrix: 50 parts, Polymer modifier: 10 parts, Aluminum sulfate: 5 parts, Quartz sand: 16 parts, Polycarboxylate superplasticizer: 1.5 parts, Magnesium hydroxide: 2 parts, Cellulose ether thickener: 0.3 parts.

[0012] Preferably, the cement matrix is cement powder with a grade of 52.5, and the specific surface area of the cement matrix is 300 m 2 / kg; the particle size of the aluminum sulfate is 100-200 mm; the mesh number of the quartz sand is 80-120 mesh; the particle size of the magnesium hydroxide is 50-150 mm.

[0013] Preferably, the preparation method of the polymer modifier is as follows: Add 2 g of ferric chloride to 10.0 mL of dopamine hydrochloride solution, ultrasonically treat it at 60 W for 5 min, and then stir it with a magnetic stirrer at room temperature for 24 h; then, centrifuge the obtained mixture at a speed of 12,000 rpm for 10 min, wash the supernatant twice with deionized water, freeze-dry it in a freeze dryer for 24 h to obtain a black powder. Then, add 10 g of methyltrifluoroethyl carbonate and 30 mL of deionized water, continuously shake it at 160 °C for 12 h, wash the precipitate twice with PBS buffer solution, and dry it at 60 °C and weigh it to obtain.

[0014] Preferably, the mass concentration of the dopamine hydrochloride solution is 3 mg / mL, and the CAS number of dopamine hydrochloride is 62-31-7.

[0015] Preferably, the polycarboxylate-based water reducer is one of polyester polycarboxylate water reducer, polyether polycarboxylate water reducer, and amphoteric polycarboxylate water reducer; Variety: Polyester polycarboxylate water reducer Rheobuild 1000, Manufacturer: Sika AG; Variety: Polyether polycarboxylate water reducer Master Glenium SKY, Manufacturer: BASF Construction Chemicals; Variety: Amphoteric polycarboxylate water reducer Superplasticizer K, Manufacturer: Fritz-Pak. The addition of the polycarboxylate-based water reducer is only to improve the effect and is a non-essential component.

[0016] The cellulose ether thickener is one of carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and ethyl hydroxyethyl cellulose. The length of the cellulose ether thickener is 50 μm and the diameter is 70 μm.

[0017] For example, the preparation method of the above high-efficiency quick-setting hole-sealing material includes the following steps: Mix the cement matrix, polymer modifier, aluminum sulfate, quartz sand, polycarboxylate-based water reducer, magnesium hydroxide, and cellulose ether thickener, and add 0.25 times the amount of water, and stir and mix evenly.

[0018] Beneficial effects

[0019] The polymer modifier plays a key role in the entire high-efficiency rapid-setting hole-sealing material, as follows: In this step, 2 g of ferric chloride is added to 10.0 mL of dopamine hydrochloride solution. Ferric chloride is a trivalent iron ion, and its strong oxidizing property can react with dopamine hydrochloride to induce the polymerization of dopamine, thereby forming a dopamine polymer. This polymer is generated through an oxidative polymerization reaction. The oxidizing property of the trivalent iron ion promotes the formation of covalent bonds between dopamine molecules in the form of quinoneamine, resulting in the production of polydopamine (PDA). This polymerization process is autocatalytic and can form a functionalized coating on the surface of different types of substrates. Apply ultrasonic treatment at 60 W for 5 min. By generating high-frequency mechanical vibrations, this process provides a strong shear force, which can promote the mixing of the solution and the reaction rate. Ultrasonic treatment can generate a microenvironment of transient high temperature and high pressure, enhance the interaction efficiency between reactants, and promote the oxidative polymerization reaction of dopamine. In addition, it can effectively remove the bubbles in the solution and improve the uniformity of the reaction. Stir with a magnetic stirrer at room temperature for 24 h. Constant stirring during this process ensures that the solution reaches a uniform reaction state and avoids insufficient local reaction. At the same time, this continuous stirring can maintain the temperature of the system consistent and the effective collision of reactants, improving the overall efficiency of the reaction. Long-term stirring also helps to fully disperse the generated dopamine polymer and promote the subsequent solid-liquid separation effect. After the mixture is centrifuged at 12,000 rpm for 10 min, it is washed twice with deionized water. The purpose of high-speed centrifugation is to separate the generated precipitate from the solution by rapid rotation. The centrifugal force can cause the heavier polymer to deposit at the bottom, while the light liquid floats on the upper layer, which is convenient for separation. Washing with deionized water helps to remove the unreacted substances and other dissolved impurities, improving the purity of the final product. A black powder is obtained through a freeze dryer. Freeze drying is usually used for compounds with high stability, especially in the case of removing residual moisture in the environment. The freeze-drying process directly sublimes the water molecules in the solid substance into gas by reducing the temperature and pressure, thereby protecting the structural integrity of the chemical product, improving its storage stability and redispersibility. This solvent-free process also avoids potential interference with the polymer properties. Add 10 g of methyltrifluoroethyl carbonate and heat to 160 °C and shake continuously for 12 h. Methyltrifluoroethyl carbonate can be used as a fluorinated additive to improve the chemical corrosion resistance of the polymer. At this temperature, methyltrifluoroethyl carbonate can react with the black powder to form covalent bonds, endowing the polymer with higher chemical stability and functional characteristics. Its additional functions also include improving the film-forming property of the polymer and the durability after use. Finally, it is neutralized twice by washing with PBS buffer and dried at 60 °C. The purpose of this step is to further remove the excess reagents and by-products and enhance the purity and stability of the product. The PBS buffer can maintain an appropriate pH value and avoid excessive hydrolysis reaction of the polymer containing ester bonds and other sensitive groups.After this treatment, drying at 60°C can expel the residual moisture to obtain the finished product.

[0020] Mechanistically, the polymer modifier may act in the following ways: enhancing the microstructure: strong bonding is formed between the polymer and the cement matrix, improving the consistency and stability of the internal structure of the material. Filling and sealing: polymer particles are filled between cement particles, reducing the porosity and improving the sealing performance of the material. Promoting chemical reactions: certain polymers may participate in the cement hydration reaction, accelerating the reaction process and shortening the setting time.

[0021] In summary, the polymer modifier provides significant advantages for high-efficiency quick-setting hole-sealing materials by improving mechanical properties, enhancing the sealing effect, and shortening the setting time. These characteristics make it have broad prospects in engineering applications that require rapid response and high-performance requirements. By optimizing the type and dosage of the polymer, the material properties can be further improved to meet specific needs. Brief Description of the Drawings

[0022] Figure 1 It is a scanning electron microscope image of the sample prepared in Example 5 of the present invention. Detailed Embodiments

[0023] The reagents involved in the present invention are all of analytical grade. In actual operation, parts by weight are equivalent to kilograms.

[0024] Among them, the polycarboxylate-based water reducer is one of polyester-type polycarboxylate water reducer, polyether-type polycarboxylate water reducer, and amphoteric polycarboxylate water reducer; variety: polyester-type polycarboxylate water reducer Rheobuild 1000, manufacturer: Sika AG; variety polyether-type polycarboxylate water reducer Master Glenium SKY, manufacturer: BASF Construction Chemicals; variety: amphoteric polycarboxylate water reducer Superplasticizer K, manufacturer: Fritz-Pak. Among them, the cellulose ether thickener is one of carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and ethyl hydroxyethyl cellulose. The length of the cellulose ether thickener is 50um and the diameter is 70um.

[0025] Example 1

[0026] The high-efficiency quick-setting hole-sealing material, in parts by weight, includes the following components: cement matrix: 40 parts, polymer modifier: 15 parts, aluminum sulfate: 3 parts, quartz sand: 20 parts, polycarboxylate-based water reducer: 0.5 part, magnesium hydroxide: 3 parts, cellulose ether thickener: 0.1 part.

[0027] Among them, the cement matrix is cement powder, its grade is 52.5, and the specific surface area of the cement matrix is 300m 2 / kg; wherein the particle size of aluminum sulfate is 100 mm; the mesh number of quartz sand is 120 mesh; the particle size of magnesium hydroxide is 50 mm.

[0028] The preparation method of the polymer modifier is as follows: Add 2 g of ferric chloride to 10.0 mL of dopamine hydrochloride solution, ultrasonically treat it at 60 W for 5 min, and then stir it with a magnetic stirrer at room temperature for 24 h; After that, centrifuge the obtained mixture at a speed of 12000 rpm for 10 min, wash the supernatant twice with deionized water, freeze-dry it in a freeze dryer for 24 h to obtain a black powder, then add 10 g of methyltrifluoroethyl carbonate and 30 mL of deionized water, continuously shake it at 160 °C for 12 h, wash the precipitate twice with PBS buffer solution, dry it at 60 °C and weigh it to obtain. The mass concentration of the dopamine hydrochloride solution is 3 mg / mL. The polycarboxylate-based water reducer is a polyester-type polycarboxylate water reducer; the cellulose ether thickener is carboxymethyl cellulose.

[0029] The preparation method of the high-efficiency quick-setting hole-sealing material is as described above, including the following steps: Mix the cement matrix, polymer modifier, aluminum sulfate, quartz sand, polycarboxylate-based water reducer, magnesium hydroxide, and cellulose ether thickener, and add 0.25 times of water, and stir and mix evenly.

[0030] Example 2

[0031] The high-efficiency quick-setting hole-sealing material, in parts by weight, includes the following components: Cement matrix: 60 parts, Polymer modifier: 5 parts, Aluminum sulfate: 8 parts, Quartz sand: 10 parts, Polycarboxylate-based water reducer: 2 parts, Magnesium hydroxide: 1 part, Cellulose ether thickener: 0.5 part.

[0032] The cement matrix is cement powder, its grade is 52.5, and the specific surface area of the cement matrix is 300 m 2 / kg; wherein the particle size of aluminum sulfate is 200 mm; the mesh number of quartz sand is 80 mesh; the particle size of magnesium hydroxide is 150 mm.

[0033] The preparation method of the polymer modifier is as follows: Add 2 g of ferric chloride to 10.0 mL of dopamine hydrochloride solution, ultrasonically treat it at 60 W for 5 min, and then stir it with a magnetic stirrer at room temperature for 24 h; After that, centrifuge the obtained mixture at a speed of 12000 rpm for 10 min, wash the supernatant twice with deionized water, freeze-dry it in a freeze dryer for 24 h to obtain a black powder, then add 10 g of methyltrifluoroethyl carbonate and 30 mL of deionized water, continuously shake it at 160 °C for 12 h, wash the precipitate twice with PBS buffer solution, dry it at 60 °C and weigh it to obtain. The mass concentration of the dopamine hydrochloride solution is 3 mg / mL. The polycarboxylate-based water reducer is a polyether-type polycarboxylate water reducer; the cellulose ether thickener is hydroxyethyl cellulose.

[0034] The preparation method of the above-mentioned high-efficiency quick-setting hole-sealing material comprises the following steps: Mix a cement matrix, a polymer modifier, aluminum sulfate, quartz sand, a polycarboxylate superplasticizer, magnesium hydroxide, and a cellulose ether thickener, and add 0.25 times the amount of water, and stir and mix evenly.

[0035] Example 3

[0036] The high-efficiency quick-setting hole-sealing material, by weight, comprises the following components: 45 parts of a cement matrix, 12 parts of a polymer modifier, 3 parts of aluminum sulfate, 20 parts of quartz sand, 0.5 part of a polycarboxylate superplasticizer, 3 parts of magnesium hydroxide, and 0.1 part of a cellulose ether thickener.

[0037] Among them, the cement matrix is cement powder with a grade of 52.5, and the specific surface area of the cement matrix is 300 m 2 / kg; among them, the particle size of aluminum sulfate is 200 mm; the mesh number of quartz sand is 80 mesh; the particle size of magnesium hydroxide is 150 mm.

[0038] The preparation method of the polymer modifier is as follows: Add 2 g of ferric chloride to 10.0 mL of a dopamine hydrochloride solution, perform ultrasonic treatment at 60 W for 5 min, and then stir with a magnetic stirrer at room temperature for 24 h; then, centrifuge the obtained mixture at a speed of 12,000 rpm for 10 min, wash the supernatant twice with deionized water, and freeze-dry in a freeze dryer for 24 h to obtain a black powder. Then, add 10 g of methyltrifluoroethyl carbonate and 30 mL of deionized water, continuously shake at 160 °C for 12 h, wash the precipitate twice with PBS buffer solution, and dry at 60 °C and weigh to obtain. Among them, the mass concentration of the dopamine hydrochloride solution is 3 mg / mL. Among them, the polycarboxylate superplasticizer is an amphoteric polycarboxylate superplasticizer; among them, the cellulose ether thickener is hydroxypropyl methyl cellulose.

[0039] The preparation method of the above-mentioned high-efficiency quick-setting hole-sealing material comprises the following steps: Mix a cement matrix, a polymer modifier, aluminum sulfate, quartz sand, a polycarboxylate superplasticizer, magnesium hydroxide, and a cellulose ether thickener, and add 0.25 times the amount of water, and stir and mix evenly.

[0040] Example 4

[0041] The high-efficiency quick-setting hole-sealing material, by weight, comprises the following components: 55 parts of a cement matrix, 8 parts of a polymer modifier, 8 parts of aluminum sulfate, 12 parts of quartz sand, 2 parts of a polycarboxylate superplasticizer, 1 part of magnesium hydroxide, and 0.5 part of a cellulose ether thickener.

[0042] Among them, the cement matrix is cement powder with a grade of 52.5, and the specific surface area of the cement matrix is 300 m 2 / kg; wherein the particle size of aluminum sulfate is 200 mm; the mesh number of quartz sand is 120 meshes; the particle size of magnesium hydroxide is 150 mm.

[0043] The preparation method of the polymer modifier is as follows: Add 2 g of ferric chloride into 10.0 mL of dopamine hydrochloride solution, perform ultrasonic treatment at 60 W for 5 min, and then stir with a magnetic stirrer at room temperature for 24 h; thereafter, centrifuge the obtained mixture at a speed of 12,000 rpm for 10 min, wash the supernatant twice with deionized water, and freeze-dry in a freeze dryer for 24 h to obtain a black powder. Then, add 10 g of methyltrifluoroethyl carbonate and 30 mL of deionized water, continuously shake at 160 °C for 12 h, wash the precipitate twice with PBS buffer solution, dry at 60 °C and weigh to obtain it. The mass concentration of the dopamine hydrochloride solution is 3 mg / mL. The polycarboxylate superplasticizer is a polyester polycarboxylate superplasticizer; the cellulose ether thickener is ethyl hydroxyethyl cellulose.

[0044] The preparation method of the above high-efficiency quick-setting hole-sealing material includes the following steps: Mix the cement matrix, polymer modifier, aluminum sulfate, quartz sand, polycarboxylate superplasticizer, magnesium hydroxide, and cellulose ether thickener, and add 0.25 times of water, and stir and mix evenly.

[0045] Example 5

[0046] The high-efficiency quick-setting hole-sealing material, in parts by weight, includes the following components: cement matrix: 50 parts, polymer modifier: 10 parts, aluminum sulfate: 5 parts, quartz sand: 16 parts, polycarboxylate superplasticizer: 1.5 parts, magnesium hydroxide: 2 parts, cellulose ether thickener: 0.3 part.

[0047] The cement matrix is cement powder, its grade is 52.5, and the specific surface area of the cement matrix is 300 m 2 / kg; wherein the particle size of aluminum sulfate is 150 mm; the mesh number of quartz sand is 100 meshes; the particle size of magnesium hydroxide is 100 mm.

[0048] The preparation method of the polymer modifier is as follows: Add 2 g of ferric chloride into 10.0 mL of dopamine hydrochloride solution, ultrasonic treat it at 60 W for 5 min, and then stir it with a magnetic stirrer at room temperature for 24 h; After that, centrifuge the obtained mixture at a speed of 12,000 rpm for 10 min, wash the supernatant twice with deionized water, and freeze-dry it in a freeze dryer for 24 h to obtain a black powder. Then, add 10 g of methyl trifluoroethyl carbonate and 30 mL of deionized water, continuously shake it at 160 °C for 12 h, wash the precipitate twice with PBS buffer solution, dry it at 60 °C and weigh it to obtain the product. The mass concentration of the dopamine hydrochloride solution is 3 mg / mL. The polycarboxylate superplasticizer is a polyester-type polycarboxylate superplasticizer; The cellulose ether thickener is hydroxypropyl methyl cellulose.

[0049] The preparation method of the high-efficiency quick-setting hole-sealing material is as described above, including the following steps: Mix the cement matrix, polymer modifier, aluminum sulfate, quartz sand, polycarboxylate superplasticizer, magnesium hydroxide, and cellulose ether thickener, and add 0.25 times the amount of water, and stir and mix evenly.

[0050] Control group

[0051] The high-efficiency quick-setting hole-sealing material, by weight, includes the following components: Cement matrix: 50 parts, Aluminum sulfate: 5 parts, Quartz sand: 16 parts, Polycarboxylate superplasticizer: 1.5 parts, Magnesium hydroxide: 2 parts, Cellulose ether thickener: 0.3 part.

[0052] The cement matrix is cement powder, its grade is 52.5, and the specific surface area of the cement matrix is 300 m 2 / kg; The particle size of the aluminum sulfate is 150 mm; The mesh number of the quartz sand is 100 mesh; The particle size of the magnesium hydroxide is 100 mm.

[0053] The preparation method of the high-efficiency quick-setting hole-sealing material is as described above, including the following steps: Mix the cement matrix, aluminum sulfate, quartz sand, polycarboxylate superplasticizer, magnesium hydroxide, and cellulose ether thickener, and add 0.25 times the amount of water, and stir and mix evenly.

[0054] The test plan is as follows: Refer to ASTM C78-16 to test the hole-sealing material, and at the same time refer to GB / T 35159–2017 to determine the setting time. The specimen size for the flexural strength test is 40mm×40mm×160mm, and the loading speed is 0.02mm / min. After the flexural strength test, conduct a compressive strength test on the broken specimen. The cross-sectional size of the specimen fixture for the compressive test is 40mm×40mm, and the height is 40mm, with a loading rate of 0.12mm / min. The impermeability test is carried out according to the test method for the relative permeability coefficient of concrete in SL352-2020. The specimen size for the impermeability test is 80mm in bottom diameter, 70mm in top diameter, and 30mm in height. After curing in a standard curing box for 28d, conduct the test. During the test, control the constant pressure at 0.5MPa for a duration of 2h; finally, take out the specimen and split it, record the water seepage height of the cross-section, and calculate the relative permeability coefficient.

[0055] Table 1 Test Results

[0056]

[0057] At the same time, use the sample of Example 5 (the specimen for the flexural strength test) to conduct a scanning electron microscope test. As Figure 1 shown, it can be seen that the structure is uniform and smooth. The high-efficiency quick-setting hole-sealing material prepared by the present invention not only improves the mechanical strength by introducing a polymer modifier, but also improves the airtight performance and construction efficiency. These characteristics give it significant advantages in applications such as mine gas drainage that require rapid and efficient sealing.

[0058] In the comparative example, after removing the polymer modifier, both the flexural strength and the compressive strength decreased significantly. Specifically: Flexural strength: The flexural strength of the comparative example was 6.4 MPa, which was about 15% lower than 7.5 MPa of Example 5. This indicates that the polymer modifier played an important role in improving the toughness of the material and resisting bending failure. Compressive strength: The compressive strength of the comparative example was 57.1 MPa, while that of Example 5 was 63.1 MPa, with a reduction of more than 9%. This shows that the polymer modifier not only enhanced the overall structural strength of the material but also improved the density and load-bearing capacity of the material by improving the microstructure. After removing the polymer modifier, the relative permeability coefficient of the material increased significantly. The polymer modifier reduced the permeability of the material by filling micro-pores or improving the interfacial bonding of the material. After removal, there were more unfilled pores or cracks inside the material, resulting in easier penetration of gas or liquid. Weakening of structural integrity: The high permeability coefficient also reflects that the internal structure of the material is not dense enough, which is consistent with the reduction in strength. After removing the polymer modifier, the initial setting time and the final setting time were significantly extended, reaching 7800 s and 14600 s respectively. This indicates: Slowing down of the setting speed: The polymer modifier accelerated the hydration reaction of the cement matrix through chemical reactions or physical doping, thus shortening the setting time. After removal, the cement matrix lacked sufficient reaction activity or catalytic effect. Reduction of construction efficiency: The extended setting time means that it takes longer to wait for the material to solidify in practical applications, which is disadvantageous in emergency construction or rapid sealing scenarios.

[0059] In summary, the polymer modifier plays a key role in the high-efficiency quick-setting hole-sealing material, and its main contributions include: Enhancing mechanical properties: By improving the flexural and compressive capacities of the material, it shows better durability when subjected to external forces. Improving airtight performance: Reducing the permeability coefficient, effectively preventing gas or liquid leakage, and improving safety. Accelerating the setting process: Shortening the initial setting time and the final setting time, and improving construction efficiency. Therefore, when developing new hole-sealing materials, the selection and proportioning of the polymer modifier should be fully considered to optimize the material properties and meet specific application requirements.

[0060] The above has described the preferred embodiments of the present invention in detail, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the gist of the present invention.

Claims

1. An efficient quick-setting hole-sealing material, characterized in that, By weight, it includes the following components: Cement matrix: 40 - 60 parts, Polymer modifier: 5 - 15 parts, Aluminum sulfate: 3 - 8 parts, Quartz sand: 10 - 20 parts, Polycarboxylate superplasticizer: 0.5 - 2 parts, Magnesium hydroxide: 1 - 3 parts, Cellulose ether thickener: 0.1 - 0.5 parts; The preparation method of the polymer modifier is as follows: Add 2 g of ferric chloride into 10.0 mL of dopamine hydrochloride solution, ultrasonically treat it at 60 W for 5 min, and then stir it with a magnetic stirrer at room temperature for 24 h; After that, centrifuge the obtained mixture at a speed of 12000 rpm for 10 min, wash the supernatant twice with deionized water, freeze-dry it in a freeze dryer for 24 h to obtain a black powder. Then, add 10 g of methyltrifluoroethyl carbonate and 30 mL of deionized water, continuously shake it at 160 °C for 12 h, wash the precipitate twice with PBS buffer solution, dry it at 60 °C and weigh it to obtain; The cement matrix is cement powder with a grade of 52.5, and the specific surface area of the cement matrix is 300 m 2 / kg; The particle size of the aluminum sulfate is 100 - 200 mm; The mesh number of the quartz sand is 80 - 120 mesh; The particle size of the magnesium hydroxide is 50 - 150 mm; The mass concentration of the dopamine hydrochloride solution is 3 mg / mL.

2. The high-efficiency quick-setting hole-sealing material according to claim 1, wherein, It comprises the following components by weight parts: cement matrix: 45 - 55 parts, polymer modifier: 8 - 12 parts, aluminum sulfate: 3 - 8 parts, quartz sand: 12 - 20 parts, polycarboxylate superplasticizer: 0.5 - 2 parts, magnesium hydroxide: 1 - 3 parts, cellulose ether thickener: 0.1 - 0.5 part.

3. The high-efficiency quick-setting hole-sealing material according to claim 2, wherein It comprises the following components by weight parts: cement matrix: 50 parts, polymer modifier: 10 parts, aluminum sulfate: 5 parts, quartz sand: 16 parts, polycarboxylate superplasticizer: 1.5 parts, magnesium hydroxide: 2 parts, cellulose ether thickener: 0.3 part.

4. The high-efficiency quick-setting hole-sealing material according to claim 1, wherein The polycarboxylate superplasticizer is one of polyester polycarboxylate superplasticizer, polyether polycarboxylate superplasticizer, and amphoteric polycarboxylate superplasticizer; the cellulose ether thickener is one of carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, and ethyl hydroxyethyl cellulose.

5. The preparation method of the high-efficiency quick-setting hole-sealing material according to claim 1, characterized in that It comprises the following steps: Mix the cement matrix, polymer modifier, aluminum sulfate, quartz sand, polycarboxylate superplasticizer, magnesium hydroxide, and cellulose ether thickener, and add 0.25 times of water, then stir and mix evenly.

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